1. Field of the Invention
The present invention relates to a low-frequency electrotherapeutic device, specifically, to that wherein its low-frequency voltage has a ratio of positive voltage component to negative voltage component in the range of about 0.1:1-0.5:1.
2. Description of the Prior Art
In a massotherapy wherein a low-frequency voltage is applied to human body, it is recommendable to use a low-frequency voltage with a sharp waveform consisting of a rapid rise and a slow fall. Low-frequency voltages with a logarithmic or square waveform have been frequently used in the past because they fulfill these requirements.
The low-frequency voltages may achieve a satisfactory efficacy when their duration conforms to the chronaxy of the muscle being treated, but frequently lead to a painful unsatisfactory treatment because the chronaxy greatly varies with individual sites in a human body.